polarisation, refraction, em waves, reflection

Question 1

total internal reflection

Answer 1

when light travels from a material of a higher refractive index to one of a lower refractive index

both refraction and a weak reflected ray occur

Question 2

Gamma rays

Answer 2

10^-10 to 10^-16

Sterilisation, cancer treatment

Question 3

X-rays

Answer 3

10^-8 to 10^-13

Security, bone imaging

Question 4

Ultraviolet

Answer 4

400nm to 10^-8

Sun tanning, counterfeit detection

Question 5

Visible light

Answer 5

700nm to 400nm

Sight

Question 6

Infrared

Answer 6

10^-3 to 700nm

Remotes, thermal imaging, heaters

Question 7

Microwaves

Answer 7

10^-1 to 10^-3

Communication, cooking

Question 8

radio waves

Answer 8

10^6 to 10^1

communication

Question 9

refraction

Answer 9

the changing of direction of a wave as it enters a different medium due to a change in speed.

The light enters glass from air, the speed decreases which causes the direction to change.

Question 10

reflection

Answer 10

angle of incidence= angle of refraction

The direction of a wave changing as it meets a surface.

The wave is bounced back when it hits a boundary.

Question 11

polarising filter

Answer 11

produces plane-polarised light by selective absorption of one component of the incident oscillations-

the filter transmits only the component of light polarised perpendicular to that direction

Question 12

plane-polarised wave

Answer 12

oscillations of the field and the direction of travel are confined to a single plane

Question 13

What do all EM waves have in common?

Answer 13

travel through a vacuum

possess both a magnetic wave and an electrical wave interlocked and at right angles to each other

travel at the speed of light

transverse waves

reflected, refracted and diffracted

demonstrate interference

be polarised

Question 14

electromagnetic wave

Answer 14

a self- spreading transverse wave that does not require a medium to travel through

Question 15

plane of polarisation

Answer 15

the plane in which a wave vibrates

Question 16

plane polarisation

Answer 16

If a transverse wave is incident on a polariser, oscillations perpendicular to the motion are restricted to one plane only

light is partially polarised on reflection

Question 17

refractive index

Answer 17

refractive index=
speed of light in a vacuum/speed of light in that material

n=c/v

Question 18

snell’s law

Answer 18

n1sinθ1 = n2sinθ2

Question 19

absolute refractive index

Answer 19

ratio between the speed of light in a vacuum, c, and the speed of light in that material, v.

Question 20

unpolarised light

Answer 20

light that is oscillation at any direction

Question 21

Malus’s law

Answer 21

describes change in intensity of a transverse wave passing through a Polaroid analyser

when the plane polarised, light hits the analyser at an angle θ to the polarised light,

the amplitude of the light is changed

I = I0 cos2θ

Question 22

total internal reflection

Answer 22

at angles of incidence greater than C, refraction is impossible.

that means all the light is reflected back into the material

Question 23

determining critical angle

Answer 23

sinC = n2/n1